Counter-blow forging hammer



Dec. 1, 1959 E. H. KENDALL ETAL 2,914,971

COUNTER-BLOW FORGING HAMMER Filed May 28, 1957 5 Sheets-Sheet 1INVENTORS Edgar H.Kendo|l Ho dTer I e 8 By Du I .Lo 0rd Dec. 1, 1959Filed May 28, 1957 E. H. KENDALL ETA]- COUNTER-BLOW FORGING HAMMER 5Sheets-Sheet 2 Fig.2

Dec. 1, 1959 E. H. KENDALL ETAL COUNTER-BLOW FORGING HAMMER Filed May28, 1957 5 Sheets-Sheet 3 Fig.3

Dec. 1, 1959 KENDALL ETAL 2,914,971

COUNTER-BLOW FORGING HAMMER Filed May 28, 1957 5 SheQtS -Sheet 5 UnitedStates Patent 2,914,971 COUNTER-BLOW FORGING HAMMER Edgar H. Kendall andHoward Terhune, Alliance, and

Daniel L. Lombard, Youngstown, Ohio, assignors of one-half to LombardCorporation, a corporation of Ohio, and one-half to E. Homer Kendall,doing hush ness as Kendall Engineering Company Application May 28, 1957,Serial No. 662,282

8 Claims. or. 78-42) This invention relates to counter-blow forginghammers of relatively large capacity and moreparticularly to supportmeans for a counter-blow hammer which will minimize bending and twistingmoments in the structural members of the hammer. 1

As the name implies, counter-blow forging hammers are those in whichaforging is formed between a pair of relatively movable forging ramswhich are forced together into engagement along a vertical axis. Thearrangement is such that as an upper ram moves downward, it transmitsforce through a fluid transmission system to a lower ramwhich movesupward to meet the downwardly moving ram.

It has been common practice in the construction of counter-blow hammersto provide a base or foundation which supports a plurality of uprightcolumns for guiding the rams along their vertical path of travel. Theupper extremities of the columns are interconnected by a large heavycrosshead which normally carries a steam cylinder or other similardevice which provides motive power to force the rams into engagement.Although hammers of this type have proved to be successful in certaininstallations, they are, generally considered to be impractical forforgings of great length or width where very high forging pressures arerequired. Usually the shape of the forging 'dies is such that an unevenloading will be produced on the rams when they are forced intoengagement, thereby causing the rams to twist or skew with respect totheir axial path of travel during the impact of forgingx'Since the ramsare guided by the aforesaid vertical columns, this twisting causesbending moments or deflection in the columns, resulting in highinternalstresses and mismatching of die impressions.

Heretofore, the-problem'of bending and defiection'has been attacked byattempting to provide columns having the requisitestrengthcharacteristics to take such loadings. For example,' fone method *hasbeen to laminate the vertical columns a'nd crosshe ad so that thelaminae making up the structural members are free to move relativeto''each other and are thusstressed separately. The present invention,{on the other hand, solves the problem of bending and deflection, not byattempting to design columns and other-supportm'embers which willwithstand severe internal stresses, but by providing an entirely newcounter-blow hammer configuration which will minimize or eliminatebending'moments in the structural members of the hammer:

Accordingly, it'is afprimary object of this invention to provide a i newand improved counter-blow hammer arrangement. i

Morespecifically, an objectof the invention is to provide a counterblowdorging hammer in which bending and deflection of 'th'e'structuralmembers of the hammer are minimized;

Another object'of the invention is to provide means for supportinga-count'er-blow hammer against gravity in a plane which is in closeproximity to the plane of engagement of "the twoforgingrams of thehammer.

, 2,914,971 Patented Dec. 1, 1959 A still further object of theinvention is to provide a new and improved hydraulic force transmissionsystem for a counter-blow hammer.

in one embodiment of the invention, hereinafter described, there isprovided an integral frame member ineluding a pair of lateral guidingand supporting members located on either side of two forging rams. Theframe is suspended on the upper edges of a generally cup-shapedfoundation by projectings which extend outwardly from the lateralguiding members, the arrangement being such that a portion of the frameextends into the cavity formed by the cup-shaped foundation. By locatingthese projections in close proximity to the plane of engagement of theforging rams, and by securing the projections to the upper edges of thecup-shaped foundation, an external lateral support is provided for theram guides at a point where maximum deflection would occur, therebyminimizing or eliminating such bending.

The above and other objects and features of the invention will becomeapparent from the following detailed description taken in connectionwith the accompanying drawings which form a part of this specification,and in which: Figure 1 is a plan view of one embodiment of the1I1V611l1011;.

Fig. 2 is a partially broken away side view of the embodiment shown inFig. 1;

Fig. 3 is a sectional view taken along line IIIIII of Fig. 1; a

Fig. 4 is a broken away cross sectional view of the invention showingits hydraulic transmission system;

Fig. 5 is a detailed showing of aportion of the hydraulic forcetransmitting system of the invention;

Fig. 6 is a cross sectional view taken along line VI-VI of Fig. 5;

Fig. 7 is a diagrammatic view of the horizontal twisting moments andforces produced by the rams of the invention during a forging impact;and

Fig. 8 is a diagrammatic view of the vertical twisting moments andforces produced by the aforementioned rams.

Referring to Figs. 1, 2 and 3, the embodiment of the invention showncomprises an integral frame member 10 having a pair of spaced, uprightcolumns 12 and 14 which guide forging rams 16 and 18 along a verticalpath of travel. The upper extremities ofthe columns 12 and 14 areinterconnected by a crosshead 20,while the lower extremities areinterconnected by a housing structure, generally indicated at 22. Aswill be understood, the ends of the columns 12 and 14 are securelyfastened to the crosshead 20 and housing 22, respectively, by bolts orother suitable fastening means so that a composite structure is formedfor guiding'the rams l6 and 18 along their vertical paths of travel. Thecolumns 12 and 14 are joined at opposite sides by cross bars 24 and 26,substantially as shown.

Extending through the columns 12 and 14 approximately midway betweentheir opposite extremities are bars 28 and 30 which support the hammeragainst gravity. The opposite ends of the bars 28 and 30 are journaledin four bearing blocks 32 which rest on the upper edge of a generallycup-shaped foundation 34 of concrete or other suitable material. Incross section (Fig. 2) the foundation appears as a base 36 having a pairof spaced upwardly extending structures. 38 and 40 which support Carriedon crosshead 20 is a steam cylinder 42 which is controlled by a controlvalve 44. Reciprocable within cylinder 42 is a piston 46, shown in Fig.4, which is an integral part of the upper. forging ram 16, thearrangement being such that when steam under pressure is admitted tocylinder 42 above piston 46 the piston and ram 16 are forced downward.Movement of the lower ram '18"is 'effected by a hydraulic transmissionsystem, hereinafter described, which forces the lower ram 18 upward asthe upper ram 16 moves downward, and vice versa.

The hydraulic system for controlling ram 18 is best shown in Figs. 2 and4 and comprises a pair of tubular rods 48 and 50 positioned on eitherside of the central axis of the hammer. The opposite ends of each of therods 48 and 50 are provided with plugs 52 and 54. The upper plug 52extends into an annular shoulder element 56 which has a necked-downportion extending into a vertical bore 58 provided in' ram 16, while areduced diameter portion of the rod and the lower plug 54 extend intothe'hollow interior of a tubular piston 60. Surrounding element 56' betweenflange 62 and a corresponding shoulderon the ram are laminated washers64 which may, for example, comprise successive annuli of rubber andmetal to provide a cushion between ram 16 and rod 48 or 50. Similarwashers 66 surround each of the rods 48 and 50 between aninwardly-projecting flange 68 on the column 12 or 14 and a shoulder onthe underside of ram 18 to cushion and limit the downward travel of thelower ram.

Each of the pistons 60 is reciprocable within an associated cylinder 70carried within housing 22. The lower portions of the cylinders 70communicate through passages 72 with a chamber 74 in the lower portionof housing 22. Chamber 74 also communicates with a second pair of spacedcylinders 76, one of which is shown in cross section in Fig. 2.Reciprocable within cylinders 76 are tubular pistons 78 which aresimilar to the pistons 60 already described. As shown, each of thepistons 78 is connected to the lower ram 18 by a tubular rod 80, theupper extremity of which extends into an annular shoulder element 82. Acushion 84, similar to those already described, is positioned between aflange'86 on the element 82 and the upper inside surface of a bore 88 inram 18.

From the foregoing, it should be apparent that when steam is applied tothe upper surface of piston 46 to force ram 16 and rods 48 and 50downward, the resulting fluid pressure in chamber 74 forces pistons 78and ram 18 upward to meet the downwardly-moving ram 16. The A strokes ofthe rams are substantially the same so that the surfaces of dies 90 and92 which are carried by the rams meet in a plane which lies in closeproximity to the midpoint between the opposite extremities of columns 12and 14.

If, for some reason, the hydraulic transmission system is not entirelyfilled with fluid, the upper ram 16 will move downward to take up theunfilled volume before the lower ram 18 starts moving upward. This, ofcourse, increases the stroke of the upper ram. If the increase in strokeis great enough, damage may result from the pistons 60 bottoming againstthe ends of cylinders 70. To prevent such damage, the arrangement shownin Figs. and 6 is provided wherein tapered grooves 71 are employed onthe inner surface of the sleeve 73 in cylinder 70. It is apparent fromthe drawing that the cross-sectional areas. of. the orifices formed bygrooves 71 as pistons 60. overshoot and travel downward beyond passages72 gradually decrease. Consequently, the pressure beneath the pistonsincreases as their forward ends pass grooves 71, .and this increase inpressure produces a relatively: gradual deceleration of the ram 16 .andpistons 60 to prevent any' damage which-otherwise might be caused byimpact of thepistons against the bottoms of cylinders '70. It will benoted'that. since the entire lower portion of the hydraulic system iscontained within the integral housing structure 22, the possibility ofleakage is minimized. Furthermore, since the housing 22 is connected tothe lower extremities of columns 12 and 14 over a wide area, thedownward force produced on housing 22 is distributed over a wide areaalso, and the strength requirements of the individual devices forfastening these parts together are not as severe as they would be if thelower portion of the hydraulic system were broken into several parts.

In Fig. 3 it can be seen that the columns 12 and 14 are arcuate in crosssection and that, together with ram 16 or 18, they form a generallycircular configuration. The columns are hollow and are reinforced withribs extending along their inner surfaces. In order to produce matchedforgings, it is necessary for the rams 16 and 18 to be securely guidedthroughout their vertical paths of travel. Since the rams will heat upand expand during operation of the hammer, some means must be providedto allow for expansion of the rams while maintaining secure lateralguiding support for the same.

The arrangement for supporting the rams while permitting expansion dueto heating is shown in Fig. 3 and comprises four bearing surfaces 96which are radial with respect to the central axis of the forging hammer.Each of the surfaces 96 slide on cooperating bearing surfaces 98 ofwedge-shaped guide members 100 which extend along the full length of thecolumn 12 or 14. The hearing surfaces 98 are on the same radii withrespect to the central axis of the hammer as surfaces 96. Since theresultant of heat expansion and contraction forces in any part of theram will be radially disposed, any expansion or contraction of the ramwill merely result in relative sliding movement between each set ofcooperating bearing surfaces 96 and 98.

As the bearing surfaces 96, 98 wear, the guide members 100 may beadjusted to move inwardly toward the axis of the hammer. It will benoted that the surfaces on the ends of columns 12 and 14 which lieadjacent the guide members 100 are not parallel to surfaces 96, 98, butconverge toward the hammer axis. Consequently, as the surfaces 96, 98wear, the members 100 may be moved inwardly without altering the radialpositioning of the wear surfaces. For locking guide members 100 in apredetermined position, wedges 102 are provided at the rear of each ofthe guide members.

'If the shape of dies and 92 were such that only vertical forces wereproduced in the structural members of the hammer, the construction ofthe hammer would be relatively simple and no problems would arise byvirtue of deflection of various members in the hammer. In actualpractice, however, the shape of the dies is such that severe bendingand/or twisting moments will be produced in the rams during a forgingimpact. Such moments are shown in Figs. 7 and 8 wherein the vector T;

represents a horizontal bending or twisting moment pro-.

duced in the top ram 16. Remembering that for each action there must bean equal and opposite reaction, it is apparent that a twisting moment Tis produced in the lower ram 18. If the moment T tends to rotate upperram 16 in a counter-clockwise direction, it follows that the moment Ttends to rotate the lower ram 18 in a clockwise direction. Moment T thusproduces force F on one side of column 14 and force F on the other sideof column 12. In a similar manner, moment T produces force F on theupper side of column 14 (as viewed in Fig. 7) and force F on the lowerside of column 12. Forces F and F add up to produce a resultant force Ftending to bow column 14 outward; while forces F and P add up to producea resultant force F tending to bow column 12 outward.

.The advantage of supportingv columns Hand 14 approximately midwaybetween their extremities and in close proximityto the plane ofengagement of rams 16 and 18 thus becomes apparent. {Ifthe columns weresupported at one end as in conventional counter-blow hammers, theresultant forces P and P would tend to spread the columns 12 and 14 andproduce severe deflections in the same. By virtue of the uniquearrangement of the present invention for supporting the hammerapproximately midway between the opposite extremities of its lateralguiding members, the resultant forces F and P are taken directly by thebearing blocks 32 and foundation 34; and bending or deflection in thecolumns is minimized or completely eliminated.

In Fig. 8 vertical bending moments T and T are illustrated which alsotend to bow the columns 12 and 14 outward. For purposes of illustration,a workpiece 150 is shown between dies 90 and 92 which produces the twobending moments, one of which tends to rotate ram 18 clockwise and theother of which tends to rotate ram 16 counter-clockwise. The amount Tproduces force F tending to force column 12 outward, and force F tendingto force column 14 outward. Likewise, the moment T produces forces F andF Forces P and F produce a resultant force which acts against bearingblocks 32 on one side of the hammer; whereas, forces E and F produce aresultant acting against the bearing blocks on the other side of thehammer. As will be understood, the forces shown in Fig. 8, as well asthose shown in Fig. 7, would deflect the columns 12 and 14 were it notfor supporting means employed in the present invention.

Other force patterns will obviously be produced by the rams, dependingupon the placing of the workpiece and the shape of the dies. In eachcase, however, the maximum stress in columns 12 and 14 is locatedapproximately midway between their opposite extremities.

Although the invention has been shown in connection with a certainspecific embodiment, it will be readily apparent to those skilled in theart that various changes in form and arrangement of parts may be made tosuit requirements without departing from the spirit and scope of theinvention.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. A counter-blow forging hammer comprising two axially aligned andmovable forging rams which are forced together into cooperativeengagement to form a forging therebetween, an integral support frame forthe forging rams comprising a pair of spaced lateral guiding members,cross members connecting the opposite ends of said guiding members, abase member, and connections for suspending said support frame on saidbase member at a point substantially midway between said cross members.

2. A counter-blow hammer comprising a pair of axially aligned forgingrams which are forced together along a vertical axis into cooperativeengagement, a pair of vertical frame members positioned on oppositesides of said forging rams for guiding the same along said verticalaxis, means connecting the upper and lower extremities of said framemembers together into an integral structure, and means connected to saidintegral structure at a point substantially midway between said upperand lower extremities of the frame members for supporting the integralstructure against gravity.

3. A counter-blow hammer comprising a pair of axially aligned forgingrams which are forced together into cooperative engagement, an integralframe member for guiding said forging rams along a straight line path,supporting means having a base and a pair of spaced structures extendingupwardly from said base, and projections extending laterally outwardlyfrom said frame member in close proximity to the plane of engagement ofsaid forging rams for suspending the frame from the upper extremities ofsaid spaced structures.

4. A counter-blow forging hammer comprising, in combination, a pair ofaxially aligned. forging rams which.

are forced together into cooperative engagement along a vertical axis,an integral frame member for guiding said forging rams along a straightline path, a base member, and connections located in close proximity tothe plane of engagement of said rams for suspending said frame member onthe base member.

5. A counter-blow forging hammer comprising, in combination, a pair ofaxially aligned forging rams, means for forcing said rams intocooperative engagement, a pair of upright members located on eithersideof said forging rams for guiding the rams along a vertical straightline path, means connecting the respective upper and lower extremitiesof said upright members to form an integral suppolt frame for theforging rams, guiding surfaces on the upright members arranged forcooperative engagement with said rams, the guiding surface on oneupright member facing the guiding surface on the other upright member,supporting means having a base and a pair of spaced structures extendingupwardly from the base, and means for suspending said integral supportframe from the upper extremities of said spaced structures, saidlattermentioned means including a first pair of spaced projectionsextending outwardly from the side of one of said upright membersopposite its guiding surface to engage the upper extremity of one ofsaid spaced structures, and a second pair of spaced projectionsextending outwardly from the side of the other of said upright membersopposite its guiding surface to engage the upper extremity of the otherof said spaced structures.

6. A counter-blow forging hammer comprising, in combination, a pair ofaxially aligned forging rams, means for forcing said rams intocooperative engagement, an integral frame including a pair of spacedmembers located on either side of said forging rams for guiding the ramsalong a vertical path of travel, substantially U-shaped supporting meanscomprising a base having a pair of spaced structures extending upwardlyfrom the base, and projections extending outwardly from said members forsupporting said integral frame on the upper extremities of said spacedstructures.

7. The combination claimed in claim 6 in which said projections arelocated on the spaced members to offer maximum resistance to bendingforces in said members due to twisting of the rams along their path oftravel.

8. A counter-blow hammer comprising, in combination, a pair of axiallyaligned forging rams, means for forcing said rams into cooperativeengagement, an integral frame including a pair of spaced members locatedon either side of said rams for guiding the rams along a straight linevertical path, and a support structure connected to said spaced membersin close proximity to the plane of engagement of said rams to therebyoifer maximum resistance to bending forces produced in the spacedmembers due to twisting moments produced by said rams.

References Cited in the file of this patent UNITED STATES PATENTS545,758 Aiken Sept. 3, 1895 615,214 Ferguson Nov. 29, 1898 1,990,478Fitzgerald Feb. 12, 1935 2,117,575 Saives May 17, 1938 2,220,037Fitzgerald Oct. 29, 1940 2,241,787 Murray May 13, 1941 2,386,155 WeyerOct. 2, 1945 2,729,943 Clarke et a1. Jan. 10, 1956 2,807,177 TerhuneSept. 2471957 FOREIGN PATENTS 128,489 Germany May 13, 1902 467,193 GreatBritain June 14, 1937 630,111 Germany May 20, 1936 845,003 Germany Oct.30, 1952 857,118 France Apr. 8, 1940 946,404 Germany Aug. 2, 1956

